Engine starter



Feb. l0. 1925. 1,525,923

A. A. DENsMoRE ENGI NE STARTER Filed Fe 27, 1923 Patented Feb. 10, 1925.

UNITED STATES ALBERT A. DENSMORE, OF BROOKLINE, MASSACHUSETTS.

ENGINE STARTER.

Application led February 27, 1923. Serial No. 621,524.

To all whom 'it may concern.'

Be it known that I, ALBERT A. DnNsMoRE, a citizen ot' the United Statesof America, and resident of Brookline, in the county of Norfolk andState of Altlassachusetts, have invented new and useful Improvements inEngine Starters, of which the following is a specification.

This invention pertains to motor driven starters such as are employedfor stalting internal combustion engines.

Engine starters of the usual type Comprise a motor driven pinion whichautomatically moves into mesh with a gear connected with the engineshaft and thus drives the latter until the engine starts whereupon thepinion is automatically moved out of mesh 'with the gear. The operationof the starting motor is controlled hy a foot pedal and so long as thepedal is depressed the starting motor continues to run. It frequentlyhappens, hy reason of preoccupation or i arelessness ou the part oi theoperator, that the pedal is not released immediately after thc enginestarts and as the motor continues to run the pinion repeatedlyapproaches the moving gear with the result that the contacting edges ofthe teeth of the pinion and gear are rapidly worn or broken thus greatlyshortening the useful life of the starter device.

The principal object of the present invention is accordingly to providestarter mechanism so constructed and arranged that continued depressionof the starter pedal will not result in damage to the teeth of thedriving pinion or gear and more particularly to provide startermechanism with means automatically disconnecting the pinion from thestarter motor when the engine starts so that the motor and pinion mayrotate independently of each other While the pinion remains in mesh Withthe engine gear.

ln the accompanying drawings illustrating the invention:

Fig. 1 is a side elevation. partly broken away and partly in verticalsection, showing starter mechanism embodying the present invention, theparts being in their nor mal or inoperative position;

Fig. 2 is a view generally similar to Fig. 1 but showing the parts aspositioned for starting the engine;

Fig. 3 is a vertical section on the line 3-3 of-F ig. 2;

The starter motor is indicated by thek numeral 1. This motor is ofreversible type and has a shaft 2 Whose outer end is journaled in a`hearing 3 which may form a part -ot the engine frame it' desired. Theoperation of the motor is controlled by means of a foot pedal 4 having astem 5 guided to slide in an opening in the foot board 6 of the vehicleto which the starter mechanism is applied. A spring interposed betweenthe foot board and the pedal normally holds the latter in inoperativeposition. The stem is furnished with spaced contacts 5a, 6a engageablerespectively with lined contacts 5", 6b forming the terminals ot'conductor Wires 7, 7b, respectively leading to the motor. The stem 5 isconnected to the motor hy means of a conductor Wire 7. The details ofthe switch form no part of the present invention, it heing onlynecessary that upon depression of the pedal the contacts 5 and 5b firstcomplete the circuit to reverse the motor and upon further depression ofthe treadle contacts 6a, 6b complete the circuit to drive the motor inthe forward direction, the reverse operation taking place when the pedalis released.

A hollow cylindrical housingr 8 is secured to the motor frame in anydesired manner and this housing is furnished at its outer end with aradial rib or fiange 9. the housing extending slightly beyond the flangeas indicated at 10. A hollow boss 11 projects from one side of thehousing concentric with an opening through which a detent pin 12projects into the'housing, the pin being provided with a` radlal iiange.A spring 11irests upon this fiange; the other end of the spring bearingagainst a cap or cover 13 having threaded engagement with the boss.

A sleeve lo is secured by means of a. pin 1G to the shaft 2. Asubstantially cylindrical tubular pusher 18 is arranged concentric withthe shaft 2,.such pusher being interiorly screw threaded at 19 forengagement with external screw threads 17 upon the sleeve 15. Theexterior surface of this pusher is provided With a plurality oflongitudinally extending grooves or slots 20 for cooperation with thedetent pin 12, normally to prevent rotation of the pusher with theshaft. The outer end of the pusherI is provided with a plurality ot'lugs or projections 21 constituting clutch elements cooperative withshallow radial grooves 22 in a ange 23 projecting radially from the hub24 of a pinion 25. The pinion 25 with its hub is free to turn and slideon the shaft 2. The end of the hub 24 is furnished with a second radialflange 26 spaced from the flange 23 to provide an elongatecircumferentially extending groove for the reception of an annularinwardly directed flange 27 at the outer end of the pusher. A spring 28is interposed between the flange 23 of the pinion and the flange 9 ofthe housing and this spring normally tends to separate the pusher andpinion so as to take up lost motion between them and to preventrattling.

The numeral 29 indicates :an engine gear with which the pinion 25 may becaused to mesh by moving it axially along the shaft. The term enginegear is herein employed as a convenient expression for designating anygear, whether mounted directly upon the engine shaft or not, which turnssynchronously with the engine shiaft and by means of which power may `betransmitted to the latter. To facilitate entrance of the teeth of thepinion 25 into the spaces between the teeth of the gear 29, the ends ofthe teeth of the pinion may be beveled as indicated at 30. A stop collar31 is secured to the shaft 2 at a suitable point to limit movement ofthe pinion 25 and likewise to limit excess axial movement of the pusher.

The operation of the parts just described is substantially as follows,it being assumed that they. normally occupy the position shown inFig. 1. Upon depression of the pedal 4 contacts 5a and 5b are engaged,thus reversing the motor and driving the shaft in a direction whichwould tend to retract the pusher into the housing. As the pusher can atthis time move no further in this direction the detent pin 12 snaps outof the slot 20 with which it may engage and the pusher rotates with theshaft and sleeve. This action, however, is but momentary as thecontinued depression of the treadle immediately breaks contact of theparts 5'* and 5b and then brings the contacts Ga and (3l) intoengagement. As the pedal is now held in depressed condition the motorchanges its direction and the rotation of sleeve 15 causes the pusher toadvance outwardly from the housing, the detent pin holding the pusheragainst rotation of the shaft.

During the early stages of this movement the spring 2S pushes the pinion25 to the right as viewed in Fig. 1, and this movement may continueuntil the pinion 25 has been moved into mesh with the gear 29. lVhethcror not the pinion is moved fully into mesh with the gear 29 by theaction of the spring 23. the pusher will continue its movement until thelugs or projections 2l engage grooves 22 of the flange 23 whereupon, ifthe movement of the pinion has not heen completed, it will be positivelymoved until it engages the stop member 31. As axial move` ment of thepinion 25 and of the pusher is thus limited, the pusher is constrainedto partake of the rotation of the shaft 2, the detent 12 snappingsuccessivelyY from one of the slots 2U to another. The cooperatingclutch elements 21 and 22 now transmit movement of rotation from thepusher to the pinion 25 and thus drive the gear 2U until the enginestarts. As soon'as thc engine picks up speed and tends todrive thepinion 25 at a greater rate than that im .iartcd by the motor 1, thepusher backs o slightly by theaction of the screw threads 1T, 19 untilthe clutch elements are disengaged, the elongate groove in the hub ofthe pinion permitting such movement. The pinion now remains in mesh Withthe gear 29, being driven by the latter, while the shaft 2 may continueto rotate so long as the pedal is depressed. It' the pedal is notimmediately released the pusher may again advance toward the rotatingflange 23, but upon coming into Contact with the latter will immediatelywithdraw again and as the proie-tions 21 and the grooves 22 are providedwith rounded edges, no particular harm is done by repeated engagement ofthe parts. The

clutch elements shown may in many instances be replaced advantageouslyby friction surfaces of any desired material, as hereinafter more fullydescribed. Vhen the foot pedal is released the motor stops and is thenreversed for a short interval during which the pusher is retracted andthus positively withdraws the pinion 25 from the gear 29, thus restoringthe parts to the position shown in Fig. 1. As the foot pedal resumes itsnormal position the contacts 5"L and 5b are disengaged and the motorcomes to rest.

In Figs. 5 and 6 a modified form of the device is illustrated which ingeneral is similar to that above described, but differs inthe employmentof a pinion 35 having a bore of a diameter substantially larger thanthat of the shaft 2, so that in normal osition the pinion is eccentricto the shaft )referablyu to assist in holding the pinion in its normalposition, a spring 37 of any desired type is interposed between theshaft and the interior surface of the lhub 34 of the pinion. such springbeing seated in a groove in the latter surface, if desired. In thisinstance the stop member 41 corresponding to the stop 31 of the previousmodification is pro vided with a sleeve portion 42 concentric witlh theshaft and terminating in a beveled Un( 28 of Fig. l, a washer 43 isarranged con- Preferably also in place of the springwith the shaft andbearing against the inner end of the hub 34 of the pinion 235, and aspring 44 of any desired type bears against this washer and against theinterior shoulder 45 of the pusher, such spring serving to preventrattling of the parts in the same manner as the 'spring 28 abovedescribed. The projections of the pusher are here replaced by a frictionwasher 43 While the grooves of the flange 23 are omitted, the surface ofthe fiaiige being roughened or not as may be desired.

When the pusher is advanced by the niotor 1, the pinion-35 rides up onthc bevel surface 43 of the sleeve 42 until it bears upon the sleeve 42.In this position the pinion meshes with the gear 29 and the Washer 43frictionally engages fiange 23, the operation of the parts beingsubstantially like that previously described. When, however, the pinionis retracted it moves down off of the sleeve 42 into the position shownin Fig. 5, Where it cornes to rest.

I claim:

l. An engine starter comprising in combination with an engine gear, apinion for driving the latter, a reversible motor, and means actuated bythe motor, when turning in one direction, for advancing the inion intomesh with the engine gear and or rotating the pinion to drive the gear,and when turning in the opposite direction, for disenrraging the pinionrom the gear.

2. Gngine starter mechanism comprising a reversible motor having ashaft, a pinion, and means operative upon rotation of the motor shaft inone direction to advance the pinion into mesh with an engine gear and toclutch the pinion to the Shaft to transmit motion to the engine gear,the clutch becoming inoperative upon starting of the engine, and thepinion being moved out of mesh with the engine gear only upon reversalof the motor.

3. Engine starter mechanism comprising centrically in combination withan engine gear, a pinion movable into and out of mesh with the gear, areversible motor, and means operative upon turning of the motor in onedirection to advancetthe pinion into mesh with the gear and to rotatethe pinion to drive the gear, the pinion being automaticallydisconnected from the shaft While remaining in mesh with the gear afterthe engine starts, the parts being so constructed and arranged that thepinion is moved out of mesh with the gear only upon reversal of themotor.

4. Engine starter mechanism comprising in combination with an enginegear a rotaia;v shaft, a normally eccenlric pinion frce to turnrelatively to the shaft, actuating means for moving the pinion axiallyto cause it to mesh with the engine gear and for center'- ing the pinionrelatively to the drive shaft,

and clutch means for transmitting motion from the shaft to the pinionwhen the latter is meshed with the engine gear.

Engine starter mechanism comprising in combination with an engine gear,a drive shaft` a pinion provided with an elongated huh having anelongated circumferential groove therein and being free to turn andslide upon the shaft, a pusher movable axially of the shaft, said pusherhaving an annular {iange engaging the elongate circumferential groove inthe hub of the pinion, spring means normally tending to maintain saidHarige at one end of the groove, and means for moving the pusher axiallyto advance the pinion into mesh with the engine gear.

(3. Engine starter mechanism comprising a motor having a shaft, a pinionturning and sliding freely on the shaft, said pinion having an elongatehub terminating at opposite ends in radial ianges, an element carried bythe shaft, a pusher having threaded engagement with said element andprovided with a radial flange interposed between the flanges of thepinion hub, a fixed housing concentric with the shaft, a detentsupported by the housing, said detent being normally operative toprevent turning of the pusher, and a spring interposed between.

the housing and one of the flan es of the hub and tending to separatetlgie pusher and pinion.

T. angine starter mechanism comprising a drive shaft having a pinionfree to turn and slide thereon, the bore in the pinion being ofsubstantially greater diameter than that of the shaft, a sleeve Yfixedlysecured to the shaft having a beveled end engageable with the pinion forraising the pinion and centering it as it is moved axially of the shaft,an element carried by the shaft, and a pusher having screw threadedengagement with said element and operative to advance the gear onto thesleeve fixed to the shaft when the shaft is rotated.

8. Engine starter mechanism comprising a motor driven shaft, a pinionturning and sliding freely on the shaft, said pinion having a bore of adiameter larger than that of the shaft, a spring interposed between thepinion and shaft normally maintaining the pinion eccentric to the shaft,a pusher operable upon turning of the shaft for advancing the pinion inan axial direction, and means for centering the pinion relatively to theaxis of the shaft during its advancing movement.

9. Engine starter mechanism comprising in combination with an enginegear, a motor having a` shaft, a normally eccentric pinion free to turnand slide axially relatively to the shaft, means operating when theshaft is rotated for centering the pinion relatively to the drive shaftand moving the pinion into iso driving engagement with the engine gear,and means, including a clutch, for transmitting movement of rotationfrom the shaft to the pinion to drive the engine gear, said clutchcomprising cooperable elements, and means connecting said elementsproviding for limited relative axial movement thereof'.

10` llngine starter mechanism comprising in combination with an enginegear, a rotary and axially movable pinion engageable With the enginegear for driving the latter, means for moving the pinion into mesh withthe gear and for positively relracting the pinion from the engine gear.said means comprising disengageable clutch elements for rotating thepinion to drive the gear, the clutch elements being automaticallydisengaged when the engine starts.

11. Engine starter mechanism comprising in combination With an enginegear, a drive shaft, a pinion free to turn and slide on the shaft, saidpinion having an elongate hub provided with a radial havingscrew-threaded engagement with an element of the shaft. a spring pressedmember normally operative to prevent rotation of the pusher with the`shaft whereby upon rotation of the strained to move axiallyv andadvance the pinion into mesh with the engine gear, cooperable clutchelements for connecting the pusher and pinion. one of said clutchelements being carried bv the pusher, said element being disposedbetween the other clutch element, carried bv the pinion, and the flangeupon the hub of the pinion, and a stop collar on the shaft to limitaxial movement of the 'pinion and pusher.

12. Engine starter mechanism comprising, in combination ivith an enginegear, a motor having a shaft, an externally screw-threaded sleeve fixedto the shaft, a normally eccentric pinion free to turn and slide on theshaft, a pusher having threaded engagement with the sleeve, a springpressed pin normally operative to prevent rotation of the pusher so thatthe latter movesaxially When the shaft is rotated to advance the pinioninto mesh With the engine gear, means to center the pinion relatively tothe shaft as it advances toward the engine gear, engageL able clutchelements carried by the pinion and pusher respectively, and a stopcollar flange, a pusher shaft the pusher is conon the shaft to limitaxial movement of the pinion and pusher. l

13. Engine starter mechanism comprising in combination with an enginegear, a motor having a shaft, a normally eccentric pinion free to turnand slide on the shaft, a screw threaded sleeve fixed to the shaft, atubular pusher having threaded engagement With the sleeve, a springpressed detent normally engaging a longitudinally7 =extending element ofthe pusher to prevent rotation of the latter whereby upon rotation ot'the motor shaft the pusher moves axially to advance the pinion into meshWith the engine gear, means to center the pinion relatively to theshaft, and a stop to limit axial movement of the pinion and pusher.

let Engine starter mechanism comprising in combination With an enginegear, a drive shaft, a screw threaded member carried thereby, a pinionturning and sliding freely on the shaft, said pinion having an elongatehub provided with spaced radial flanges, a tubular substantiallycylindrical pusher having screw threaded engagement with the threadedmember upon the shaft and having an element disposed between the spacedflanges ot' the hub, said pusher being provided with a plurality ofcircnmferentially spaced, longitudinally extending slots in its outersurface, a spring pressed detent pin normally engaging one of said slotsto prevent rotation of the pusher, whereby upon rotation of the shaftthe pusher is moved axially to advance the pinion into mesh with theengine gear, and a stop for limiting such axial movement.

15. Engine starter mechanism comprising l in combination with an enginegear, a motor having a drive shaft, a normally eccentric axially movablepinion free to turn upon the drive shaft, a clutch element carried bythe pinion, a cooperating clutch element movable with the drive shaft,cooperable members carried` by the respective clutch elements to limitrelative motion thereof, and means Jfor moving the drive shaft clutchelement axially to push the pinion into mesh with the engine gear, andto center the pinion relatively to its shaft as it advances toward thegear.

Signed by me at Boston, Massachusetts. this 5th day of February, 1923.

' ALBERT A. DENSMORE.

driving engagement with the en ine gear, and means, including a clutch,or transmitting movement of rotation from the shaft to the pinion todrive the engine gear, said clutch comprising coopcrable elements, andmeans connecting said elements providing for limited relative axialmovement thereof.

10. lingine starter mechanism comprising in combination with an enginegear, a rotary and axially movable pinion engageable with the enginegear for driving the latter, means for moving the pinion into mesh withthe gear and for positively ret racting the pinion from the engine gear,said means comprising disengageabie clutch elements for rotating thepinion to drive the gear, the clutch elements being automaticallydisengaged when the engine starts.

11. Engine starter mechanism comprising in combination with an enginegear, a drive shaft, a pinion free to inrn and slide on the shaft. saidpinion having an elongate huh provided with a radial flange, a pusherhaving screw-threaded engagement with an element of the shaft, a springpressed member normally operative to prevent rotation of the pusher withthe shaft whereby upon rotation of the shaft the pusher is con.

strained to move axially and advance` the pinion into mesh with theengine gear, cooperable clutch elements for connecting the pusher andpinion. one of said clutch elements being carried by the pusher, saidele ment being disposed between the other clutch element, carried bv thepinion, and the flange upon the hub of the pinion, and a stop collar onthe shaft to limit axial movement of the pinion and pusher.

12. Engine starter mechanism comprising, in combination with an enginegear, a motor having a shaft, an externally screW-thread ed sleeve fixedto the shaft, a normally eccentric pinion free to turn and slide on theshaft, a pusher having threaded engagement with the sleeve, a springpressed pin normally operative to prevent rotation of the pusher so thatthe latter moves axially when the shaft is rotated to advance the pinioninto mesh with the engine gear, means to center the pinion relatively tothe shaft it advances toward` the engine gear, engageable clutchelements carried by the pinion and pusher respectively, and a stopcollar` on the shaft to limit axial movement of the pinion and pusher.

13. Engine starter mechanism comprising in combination with an enginegear, a motor having a shaft, a normally eccentric pinion free to turnand slide on the shaft, a sorewthreaded sleeve fixed to the shaft, atubular pusher having threaded engagement with the sleeve` a springpressed detent normally engaging a longitudinally extending element ofthe pusher to prevent rotation of the latter whereby upon rotation ofthe motor shaft the pusher moves axially to advance the pinion into meshwith the engine gear, means to center the pinion relatively to theshaft, and a stop to limit axial movement of the pinion and pusher.

M. Engine starter mechanism comprising in combination with an enginegear, a drive shaft, a screw threaded member carried thereby. a pinionturning and sliding freely on the shaft, said pinion having an elongatehub provided with spaced radial flanges, a tubular substantiallycylindrical pusher having screw threaded engagement with the threadedmember upon the shaft and hav# ing an element disposed between thespaced flanges ot' the hub, said pusher being provided with a pluralityof circumferentially spaced, longitudinally extending slots in its outersurface, a spring pressed detent pin normally engaging one of said slotsto prevent rotation of the pusher, whereby upon rotation of the shaftthe pusher is moved axially to advance the pinion into mesh with theengine gear, and a stop for limiting such axial movement.

15. Engine starter mechanism comprising in combination with an enginegear, a motor having a drive shaft, a normally eccentric axially movablepinion free to turn upon the drive shaft, a clutch element carried bythe pinion, a cooperating clutch element movn able with the drive shaft,cooperable members carried by the respective clutch elements to y limitrelative motion thereof, and means for moving the drive shaft clutchelement axially to push the pinion into mesh with the engine gear, and`to center the pinion relatively to its shaft as it advances toward thegear.

Signed by me at Boston. Massachusetts. this 5th day of February, 1923.

ALBERT A. DENSMORE.

DISCLAIMER.

1,525,923.-Albert A. Demmorqrookline, Mass. ENGINE STARTER. Y Patentdated i February 10, 1925. Disclaimer filed May 3, 1926, by thepatentee.

The words meansv for positively retracting as used in the claim means aconstruction yin which the retraction of the pinion from the engine gearis independent of the function of springs or equivalent devices; andthat the term positively as used in line 5 of claim 10 has the meaninggiven in the definition of the word positive in Funk & Wagnalls StandardDictionary, to wit, operated by mechanical power, not by springs orgravity and any broader meaning or interpretation of such `words orterms is hereby disclaimed.

[opzm'az Gazette May 18, 1926.]

DISCLAIMER.

1,525,923.-Albert A. Demmore, Brookline, Mass. ENGINE STARTER. Patentdated February 10, 1925. Disclaimer filed May, 1926, by the patentee'.

The Words means for positively retractng as used in the claim Ineens aconstruction 'in which the retraction of the pinion `from the enginegear is independent of the function of springs or equivalent devices;and that the term positively as used in line 5 of claim 10 has themeaning given in the definition of the Word positive in Funk & WagnallsStandard Dictionary, to wit, operated by mechanical power, not, bysprings or gravity; and any broader meaning or interpretation of such`Words or terms is hereby disolaimed.

[Oficial Gazette May 18, 1926.]

